Enhancing animal welfare by creating opportunities for positive affective engagement

Abstract

In line with an increasing emphasis on promoting positive welfare states in animals, this review extends previous accounts of how recent affective neuroscience observations may be used to identify and then to encourage animals to engage in reward-motivated behaviours. The terms affective states or affects are used to mean the subjective experiences, feelings or emotions that may motivate animals to behave in goal-directed ways and which may accompany success or failure to achieve those goals. These motivational affects may be positive, experienced as rewarding or pleasurable, or negative, experienced as aversive or punishing. There are two overall types: homeostasis-related negative affects that reflect an animal's internal physiological state, and situation-related positive or negative affects that reflect an animal's perception of its external circumstances. The major emphasis is on positive situation-related affects, in particular those that are potentially associated with exploration, feeding and animal-to-animal affiliative behaviours. The review introduces the new concept of positive affective engagement which represents the experience animals may have when they actively respond to motivations to engage in rewarding behaviours, and it incorporates all associated affects that are positive. For example, it would represent a state of engaged aliveness that may attend an animal's goal-directed, energised exploration of and interactions with a stimulus-rich environment. It also represents some states of equally energised, highly focused predatory stalking by carnivores or the focused and engaged foraging by herbivores when they are grazing in natural environments where food sources are abundant. Positive affective engagement may also be anticipated to accompany some aspects of reciprocated affiliative interactions between animals, the dedicated maternal nurturing and care of young, the joyfulness of rough-and-tumble play, and the eroticism and orgasmic pleasures of sexual activity. It is argued that highlighting the genetically pre-programmed, affectively positive impulses to engage in reward-motivated activities such as these, and the positive affects that may attend different facets of the process, draws attention to a wider spectrum of welfare enhancing experiences than has hitherto been considered to be important to animals. These neuroscience-supported observations strengthen many prior inferences made from predominantly behaviour-based investigations of animals' preferences, aversions and priorities, the associated development of successful environmental enrichments and the inclusion of these, where practicable, in more recent codes of practice or welfare.

A “How-To” Guide for Designing Judgment Bias Studies to Assess Captive Animal Welfare

“…First, cognitive bias measurements provide a metric for assessing positive emotions in animals. There are few, if any, objective measures of positive emotions in animals despite widespread physiological and behavioral measures of negative emotions (Mellor, 2015;Paul et al, 2005). Good welfare requires the presence of positive states and a low occurrence of negative states (Boissy et al, 2007;Dawkins, 1990;Fraser & Duncan, 1998).…”

“…Reviews of cognitive theories of emotion present the rationale for using cognitive bias measures and discuss limitations and future directions (Mellor, 2015;Mendl et al, 2009;Otovic & Hutchinson, 2015;Paul et al, 2005). ; for earlier discussion see Mendl et al, 2009;Paul et al, 2005); expectancy biases -akin to optimism and pessimism regarding future events (rats: van der Harst, Baars & Spruijt, 2003), and reward sensitivity -susceptibility to despondency following loss or failure (rats: Burman et al, 2008b).…”

Positive animal welfare states and encouraging environment-focused and animal-to-animal interactive behaviours

“…These neuroscience-supported inferences generally accord with and thereby strengthen the confidence that may be placed in previous inferences made from largely behaviour-based investigations of animals' preferences, aversions and priorities (Dawkins 2006;Kirkden and Pajor 2006;Mason and Rushen 2006). Importantly for the present analysis, this growing alignment of affective neuroscience and behavioural science observations supports the view that some goal-directed behaviours themselves and behavioural responses to success or failure in achieving those goals may be used cautiously to identify the accompanying affects (Mellor 2015a). …”

“…Affective states or affects may be understood to include all feelings or emotions that are consciously experienced as pleasant or unpleasant and which motivate animals to behave in particular ways (Mellor 2015a). Described as motivational affective states (Fraser and Duncan 1998), they are manifestations of genetically pre-programmed neurological processing that impels animals to behave in ways which are likely to have been of adaptive value in their evolutionary past (Fraser and Duncan 1998;Panksepp 2005;Boissy et al 2007).…”

“…It applies the mainly neuroscience-supported behaviour-based inferences outlined in the first review (Mellor 2015a) to describing several environment-focused and animal-to-animal interactive behaviours that seem likely to be accompanied by positive affects. It also considers factors that may influence the anticipated intensity of the positive affects experienced by animals.…”